All language subtitles for National.Geographic.Forces.Of.Nature.2004.1080p.BluRay.H264.AAC-RARBG.2_English

NARRATOR: Planet Earth, four and a half billion years ago.

A blazing sphere formed by colliding cosmic matter...

a violent world, covered by a sea of molten lava.

Over time, the surface cooled into a rocky crust.

Great clouds of water vapor rose...

then rained down, forming a vast ocean.

The crust fractured into huge, moving plates

that shifted the emerging continents...

producing the face
of the planet we know.

But the forces that created Earth
still rule it.

Around the globe sweeps
a volatile atmosphere...

and within, a fiery world still burns.

Floating on this semi-molten interior,

the plates of the crust
are forever in motion.

Only in a thin layer between the inner heat
and the atmosphere

could life arise and thrive...

yet always at the mercy
of these colossal forces...

erupting from the depths...

shaking the solid ground...

descending from the sky.

We cannot control such power.

But we can use our human powers
of invention and discovery--

to learn, to understand...

and to survive.

There are places where primal forces
are still on display,

where lava streams freely
from the earth's interior.

Yet these same forces can also
erupt suddenly, unpredictably...

with terrible consequences.

For hundreds ofyears,
a volcano called Soufriere Hills

on the Caribbean island
of Montserrat was dormant.

But in 1995, some 12,000 islanders
discovered they were living on a time bomb.

RADlO ANNOUNCERS:
The situation has escalated.

This followed a major ash fall
atjust after 8:00 this morning.

The scientists have told us that they can
no longer guarantee six hours notice.

All incoming data are being processed
on a near real-time basis

because the volcano can just go off
with little or no warning.

[siren]

[rumbling]

NARRATOR: Deadly cascades ofash, gas,
and lava rocks called pyroclastic flows

raced down the mountain at temperatures
as hot as 1,000 degrees.

The eruptions continued, burying
the capital of Plymouth under ash,

but there was time to evacuate
the population ofabout 4,000...

and no lives were lost here.

Yet outside the city,

pyroclastic flows killed 19 people
who had ignored the warnings.

Forscientists, this place has become
a kind of living laboratory.

At the Montserrat Volcano Observatory,

Dr. Marie Edmonds is part ofa team
from the British Geological Survey.

EDMONDS: l became a volcanologist

because we know so little
about these dangerous mountains...

and l saw that studying them could mean
better forecasts of eruptions,

which could save many lives.

l sometimes feel like the volcano
is almost a living thing.

lt grows, it breathes,
it even has a kind of pulse.

l grew up wanting to be
an astronaut or a spy--

but living alongside an active volcano
is just as exciting.

Right now, there are signs the mountain
is building towards another big event .

We feel a great weight of responsibility
on ourshoulders.

But it's difficult trying to figure out

what might be happening miles below
in the crust of the earth.

Montserrat is actually the peak
ofan undersea volcano

which was built up by a collision
between two plates of the earth's crust.

As the heavier plate plunges
beneath the other,

intense heat and pressures
melt the leading edge into magma.

The magma rises into a chamber
and then heads towards the surface.

lf it reaches the surface quickly,
it can generate enough gas to explode.

Smaller explosions continued here,

and during the last couple ofyears

thick magma has built
a 500-megaton mountain above the vent--

a huge lava dome.

We believe it will collapse,

and that it will trigger more explosions
and potentially dangerous pyroclastic flows.

NARRATOR The first hint
of danger comes

when seismic instruments show
increasing swarms ofearthquakes--

a sign that magma is rising,
causing tremors within the volcano.

Routine monitoring takes on
a new urgency.

They need to check the instruments
designed by Marie

that constantly monitor gases
rising from the volcano.

EDMONDS: We've discovered that ifthe volcano
suddenly exhales more gas,

it can mean that the activity
is ramping up to an eruption.

So today the volume is up,
and that's a worrisome sign.

Next we have to fly as close as possible
to the crater of the volcano

to get more data
and to evaluate the situation.

This is one of those times when
the research we conduct is a bit risky...

especially for my partner
Richard Herd.

One of his jobs is to install
a laser reflector,

which can measure even a few millimeters
of ground deformation.

That can tell us if magma
is filling the chamber below

and causing the ground to swell.

We avoid dangerous situations
unless it's absolutely necessary.

Too many researchers have died in recent years
because eruptions surprised them.

NARRATOR: All of the evidence suggests
that the dome is increasingly unstable.

The collapse seems imminent.

Warnings from the scientists convince
the government to begin evacuations.

On a July night, it happens.

[rumbling]

Violent eruptions send ash clouds
rocketing ten miles high.

[people singing Amazing Grace]

Because of the warnings,
not a single life is lost.

Ash still falls occasionally, but most
have learned to live with it.

EDMONDS: Most likely the eruptions
will pause for a while,

then begin a new eruptive cycle.

But as long as we continue
to monitor the volcano,

as long as we continue
to unravel its secrets,

there's no reason for anyone else on Montserrat
to be harmed or to lose their life...

and that in itself
is reason for celebration.

NARRATOR: What scientists
learn in Montserrat

could help reduce risk for millions of people
living near volcanoes around the world...

but there is another kind ofevent
caused by forces below

that is even harder to predict,
and far more dangerous.

Among the places at greatest risk
is a heavily populated part ofTurkey,

where shifting plates of Earth's crust
meet along a 1,000-mile seam.

lt's called the North Anatolian Fault,
and it can produce a sudden catastrophe--

one of the deadliest
ofall natural disasters--

an earthquake.

lfwe could pull the plates apart...

and descend within...

we'd see that 10 or 15 miles down

they begin turning into extremely hot,
putty-like rock,

sliding in opposite directions

atop the semi-molten interior
farther below.

Somewhere along the fault,
the plates lock together,

and over long periods of time,
enormous pressure builds.

Eventually they break loose
and rip past one another,

unleashing powerful waves ofenergy
that race through the crust,

shaking the surface above.

[man chanting]

Nearly atop the fault

lies one of the world's great cities--
lstanbul, Turkey--

which has been jolted by earthquakes
across recorded history.

ln the heart of the city,
one remarkable structure

has remained standing
through 14 centuries of quakes...

The Hagia Sophia is an enduring marvel
ofart and architecture.

But for one man, it's also a treasure-house
of geologic history.

Geophysicist Dr. Ross Stein
has spent more than a decade

studying earthquakes in Turkey,

trying to find ways offorecasting
when and where they will strike.

Here, he found a critical piece
of the puzzle.

STElN: When l first learned
that since ancient times,

the clerics of Hagia Sophia
kept records of their earthquake repairs,

l was tremendously excited.

Because with such a chronology
of quake dates and damage--

combined with other data--

we might discover a pattern that
could help us forecast quakes.

Such a discovery is
every scientist's dream.

And in some ways it came true.

lt turned out that 11 major quakes
in the last 60 years

had occurred in a largely
westward progression.

And l kept asking myselfwhy.

We went out to take a look
at each quake site,

and we began to form an idea

about how built-up stress
where the plates are locked

suddenly gets moved
during an earthquake.

We turned our data into a computer model
ofstress being transferred by a quake...

with red showing where stress
increased along the fault,

and blue where stress was relieved.

Suddenly, the puzzle pieces fit together.

With each quake,
stress didn'tjust dissipate...

but moved down the fault,
where it concentrated again.

And in most cases, a major quake struck
in the red zone where stress had increased.

Our model suggested
the next great quake

might strike lzmit, a city
of more than 200,000 people.

NARRATOR: And on August 17, 1999,
disaster did strike.

The lzmit earthquake was a magnitude 7.4
and lasted 45 seconds--

an eternity to those
who suffered through it.

[sirens]

Local news crews
captured the aftermath,

as rescuers searched for thousands
of people trapped under the rubble.

20,000 buildings were destroyed...

halfa million people left homeless.

Some believe the death toll
reached as high as 25,000.

The real toll may never be known.

The loss of life was caused in large part
by substandard construction.

ln many places,
cheaply built modern structures

lay in ruins next to undamaged
ancient mosques.

STElN: Almost immediately
after the quake hit,

the international community arrived
with food, medicine and shelters.

most of the residents
are choosing to rebuild in lzmit,

but ifthe lessons we've learned here
aren't acted upon,

their future is not bright.

The most important thing we can do
is to build safer structures--

and we know how--
we just have to make it a priority.

What l want to do
is to improve our ability

to forecast when and where
an earthquake will strike.

We calculate that stress has now
reached a segment of the fault

beneath the Sea of Marmara.

Sadly, this area where the next
major quake is most likely...

is just ten miles south of lstanbul,
a vibrant city ofsome 10 million people.

To give these millions of people a warning
just before a major quake hits,

seismometers have been placed

near the fault segment we think
is most likely to rupture.

Warnings could reach lstanbul

a mere 10 to 20 seconds
before the violent shaking waves arrive...

and the hope is that people
will have a few moments

to get themselves and their families
to a safe spot.

lt's almost impossible
to convince people

that they have a serious
earthquake problem to contend with

unless they get some kind
of dramatic warning sign...

and for lstanbul,
lzmit was that warning.

NARRATOR: The earthshaking forces beneath us
interrupt life only occasionally,

but unfolding constantly above us

is the clash of great forces
we know as weather.

The fluid gases of the atmosphere
can unleash devastating power.

This is home ofsome of the most
severe storms on Earth,

a Midwestern region of the United States
known as Tornado Alley.

ANNOUNCER: Conditions are pretty favorable
forsome explosive thunderstorm development,

in fact some of that's
going on right now.

There's going to be a threat
ofsevere thunderstorms, large hail.

The storms continuing to intensify.

Take your tornado precautions.

Do it now.

[glass breaking]

[sirens]

NARRATOR: On May 3, 1999,

an extraordinary series of tornadoes
ripped through Oklahoma

and left behind almost
unimaginable destruction.

MAN: As l remember 2x4s snapping.

They just snapped like toothpicks,
you know?

MAN: Everybody says
what do they sound like?

lt sounded pretty much
like a freight train.

But you are underneath the train.

MAN: The house was gone.

And l haven't found
the refrigeratoryet.

MAN: l looked out across the street.

And l said, there's no houses
across the street.

l can see until Fourth Street.

NARRATOR: Many survivors
were warned in time

thanks in part to an unconventional
team ofscientists.

ltwas these Doppler-radar trucks,
venturing close to the 1999 storms,

that clocked the fastest wind speed
ever recorded near the ground--

301 miles per hour.

Dr. Joshua Wurman and his team spend
months each year chasing tornadoes,

hoping to get a radar's-eye view
inside them.

WURMAN: For a long time,
l've dreamed ofsolving

the biggest mystery
about tornados--

how they're born.

my goal is to get
a three-dimensional picture

of the wind speed and wind direction
within the storm.

But first, we have to position
our two trucks

on different sides ofa storm
at roughly a 90-degree angle

and be in just the right place
as the tornado begins.

We don't know exactly
how a tornado starts...

but we do know what precedes it.

Here, warm moist air
from the Gulf of Mexico

rushes upwards through cooler air,
forming a thunderstorm.

Some of the rising air cools and sinks,
or is dragged down by rain and hail.

The warm air racing in at the bottom
can actually push on the higherwinds aloft,

sort of tilting them and forming
a large spinning column.

Somehow, down near the ground

between the air rushing up
and the air rushing down,

the spinning dramatically intensifies.

The thing that fascinates me

is that only some storms
spawn tornadoes.

lfwe could figure out which ones,
we could warn people earlier.

That's why we drive about
10,000 miles every spring.

Most of the time
we miss the tornadoes.

lt's incredibly difficult.
l've been trying foryears.

MAN: Apparently the weatherservice
is saying this storm

is capable of producing soft balls--

that's 4.5-inch hail.

l don't know if l buy it,
but l thought l'd pass that along.

NARRATOR: Near the end
of one recent season,

the team received word that
a violent storm was developing--

one that might spawn
an outbreak of tornadoes.

The challenge would be
getting there in time.

MAN: OK, both cells look pretty good.
Both have hooks on them.

The western one looks like it has
a better hook on it now.

NARRATOR: lt's a drill they've
been through many times...

one fraught with frustrations.

An empty gas tank...

empty stomachs...

inevitable indigestion....

and unpredictable delays.

[train horn blows]

This day would prove
even more eventful than usual.

MAN: The shoulders are a bit muddier
than l expected.

l tried to rock it back and forth
and when it went backwards...

and is quite stuck.

NARRATOR: The storm
was coming right at them.

All they had to do
was get unstuck.

WURMAN: Rotation is just about
due west of us.

Still about, l would say,
5 kilometers, maybe 4 1/2.

Where is the rotation
relative to you?

MAN: lt's moving directly toward us.

There's no reason
to panic on this, right?

WURMAN: Uh, not yet.

[cheering]

Are you unstuck?

MAN: Yes, yes, yes, unstuck.

WURmAN: OK, we're seeing
increasing rotation at lower levels.

Would you concurwith this?

NARRATOR: Afteryears of near misses,

Josh Wurman's team
was in perfect position--

and this storm was cooperating.

WURMAN: Curtis.

CURTlS: Stand By.

WURMAN: Curtis.

CURTlS: l'm looking at it.

We got one now.
We're getting it right now.

NARRATOR: For the first time ever,
the team succeeded

in recording with two Doppler radars

the conditions within a storm
at the moment the tornado formed.

The data will take years to analyze,

but it promises to help unravel the secret
of how this tornado was born.

lt was a victory forscience,
for Josh Wurman and his crew,

and for those whose lives will one day
be safer because of their efforts.

WURMAN: As scientists we yearn
to witness the unknown...

to see things that have
never been seen before.

Hundreds ofyears ago that would have been
new rivers or new islands.

For me that unknown
is the inside ofa tornado.

EDMONDS: Working to decipher powerful events
like a volcanic eruption

is really searching for patterns
that will alert us

when something terrible
is imminent,

so that every human life at risk
can be saved.

Only 19 people died here on Montserrat,
but that's 19 too many.

STElN: Several hundred million people

live along the world's
most active earthquake fault zones.

So it's critical we get better
at forecasting quakes.

NARRATOR: lfthese and otherscientists
can add a little bit to our understanding,

then one day the pieces
will fit together.

And we have that power--

to explore, to learn,
to find ways ofsurviving--

no matter how powerful
the forces that confront us.

ALEX: Seems to be going
northeast now.

SEAN: Hey, get me a wide lens--

get me the 40 orsomething.

ALEX: Going increasingly north,
continues at present path,

it will be rounding over
towards us.

GREG: 40-millimeter?

SEAN: Yeah.

[jiggling door handle]

SEAN: Unlock, unlock, unlock.

Open it.

Unlock it! Unlock!

GREG: Locked out?

SEAN: Yeah.